Self-tightening dunnage

ABSTRACT

Compression springs engaged between the upper and lower ends of brace slats urge the slats apart and they are held in spaced relationship by pairs of interengageable wedges, each pair having a normally fixed wedge and a normally slidable wedge. Ties adjacent to the springs hold the slats in contracted relationship against the spring pressure until released for expansion of the dunnage. Tightening is effected by automatic downward sliding of the slidable wedges relative to the normally fixed wedges. The normally fixed wedges can be released for freeing the slidable wedges to retract such wedges for contraction of the dunnage from load-clamping condition and subsequent dunnage removal.

United States Patent [191 Slusher SELF-TIGHTENING DUNNAGE [75] inventor: Leonard G. Slusher, Seattle, Wash,

[73] Assignee: Burlington Northern, Inc., St. Paul,

Minn. [22 Filed: May 2', 1972 [21] Appl. No.1 249,518

[52] US. Cl. 2l4/l0.5 R, 105/369 S [51] Int. Cl. 865g 1/14 [58] Field of Search2l4/l0.5 R, 10.5 D; 105/369 R,

105/369 B, 369 C, 369 BA, 369 S; 248/351,

[56] References Cited I UNITED STATES PATENTS 2,258,780 lO/194l Loney 105/369 S 2,022,325 11/1935 Schroeder l05/369 S 2,053,638 9/1936 Schroeder 105/369 S Jan. 29, 1974 3,095,987 7/1963 Sable IDS/10.5 D

Primary Examiner-Frank E. Werner Attorney, Agent, or Firm-Robert W. Beach [57 ABSTRACT I ward sliding of the slidable wedges relative to the normally fixed wedges. The normally fixed wedges can be released for freeing the slidable wedges to retract such wedges for contraction of the dunnage from loadclamping condition and subsequent dunnage removal.

10 Claims, 6 Drawing Figures a sworn a \T: \D

M I w PATENIED JAN 2 91974 SHEET 1 BF 2 1 SELF-TIGHTENING DUNNAGE The self-tightening dunnage of the present invention is self-expanding to facilitate its placement in loadclamping disposition.

A principal object of the invention is to provide resilient means for effecting self-expanding action of the dunnage when desired and further means for holding the dunnage in contracted relationship when such expansion is not desired.

A further object is to be able to hold the dunnage securely in load-clamping, expanded condition, while enabling the dunnage to be made contractable at will for ready removal from load-clamping disposition. It is also an object toprovide self-tightening dunnage having the capabilitiesmentioned above, which is of simple and economical construction and is light in weight so as to be readily portable.

FIG. 1 is a side elevation of the dunnage in loadclamping disposition.

FIG. 2 is a top perspective of the dunnage showing components in exploded relationship.

FIG. 3 is a side elevation of the dunnage with components moved into a relationship to conditionthe dunnage for contraction from load-clamping disposition,

and FIG. 4 is a similar view showing components of the dunnage in position for contraction of the dunnage. FIG. 5 is a similar view with the dunnage contracted and held in contracted relationship to enable it to be removed.

FIG. 6 is a side elevation of the dunnage with components in a representative relationship assumed when the dunnage is being placed in load-clamping disposition. The self-tightening. dunnage includes a brace slat l carrying pairs of cleats 2 the lengths of which extend longitudinally of the slat and which are spaced apart a distance for receiving between them normally fixed wedges 3 which taper upwardly. Such wedges can be held in fixed relationship between the cleats by pins 4 extending through aligned apertures 5 in the opposite cleats and a bore 6 in the wedge 3 which can be disposed in registration with the cleat apertures 5. The pins are secured in their positions interconnecting the wedges and the brace slat l by washers 7 engageable over the opposite ends-of the pin and held in position by cotter pins 8 extending through cotterways in the ends of pins 4.

Cooperating with the brace slat 1 is a second brace slat 9 having strips 10 forming ways extending lengths wise of such brace slat and spaced apart a distance to receive between them wedges 1 l slidable along the slat.-

While the wedges 11 are normally freely slidable downward along the brace slat 9, they can be held in position relative to such brace slat by pins 12 that can be inserted through apertures 13 in one of the strips 10 of the ways and into a bore 14 in a wedge 11 that can be placed in registration with an aperture 13. The wedges 11 are shown as being secured in stationary relationship to the brace slat 9 in FIGS. 4 and 5.

The brace slats 1 and 9 of the dunnage are selfexpanding away from each other. Such self-expanding action is effected by compression springs 15 interen gaged between the upper and lower end portions of the brace slats. One end of each spring can be suitably secured to a bearing plate 16 carried by the upper and lower end portions respectively of the brace slat l. The opposite end of each spring can be received in a socket cup 17 carried by a bearing plate 18, which bearing plates are mounted on the upper and lower ends, respectively, of the brace slat 9. When the free ends of the springs 15 arereceived in such socket cups, the

brace slats can be held in contracted relationship in opposition to the expanding force exerted by the springs 15 by restraining ties 19 shown in operation in FIG. 5.

Each tie 19, which is shown as a length of chain, has one end secured by aneye 20 to the brace slat 9. A link of such chain spaced from the eye 20 a distance corresponding to the desired contracted thickness of the dunnage can be inserted in a clevis 21 and secured by a pin 22 extending through such clevis and the selected link of the chain 19 to prevent its loss. Each pin 22 can be secured by a tether 23 to a portion of the brace slat 1 adjacent to the slevis 21 into whichsuch pin can be inserted.

Normally the self-tightening dunnage units will be held in the contracted condition-shown in FIG. 5 by the ties 19 being secured to the clevises 21 in a desired shortened condition. When thus held in contracted condition, the self-tightening dunnage unit can be stored, shipped and handled conveniently. The normally fixed wedges 3 will be held in place on the brace slat 1 by pins 4, and the normally slidable wedges 11 will be secured in fixed relationship to the brace slats 9 by pins 12. All components of the self-tightening dunnage are thus secured against movement and loss.

When it is desired to place a dunnage unit in .use, such unit is first inserted into the space between a load and a wall of the compartment in which the load is located in the condition shown in FIG. 5. The pins 12 can then be pulled, as illustrated in FIG. 6, in order to enable the wedges 11 to slide freely downward relative to the brace slat 9 between the ways 10. First a pin 22 at one end of the dunnage unit is withdrawn from its clevis 21 to free the tie 19. In FIG. 6 the upper tie is shown as having been thus freed. The adjacent spring 15 immediately serves to spread the portions of the slats 1 and 9 between which it is engaged. Spreading of slats 1 and 9 must be limited to a distance slightly less than the combined thickness of the thicker ends of a pair of wedges 3 and 11 so that the free wedges l 1 cannot drop below the lower ends of their respective cooperating wedges 3. Such limitation can be effected by reengagingpin 22 with a limiting link of tie 19.

The pin 22 will then be withdrawn from the other clevis 21 to free the other tie Use that the adjacent spring 15 can expand the other end of the dunnage. As such expansion occurs the freely slidable wedges 11 will slide downward from the positions shown in FIG. 6 to the positions shown in FIG. 1. With the wedges in this relationship the brace slats 1 and 9 will be held positively in such expanded relationship. If the load shifts away from the adjacent wall during transit of a vehicle, for example, the slidable wedges 11 will continue to move downward automatically to maintain the brace slats 1 and 9 in positively spread relationship.

of a screwdriver bit between the sliding wedge and the ways. Downward movement of the now freely slidable wedge 3 is limited by a peg 24. When the wedge 3 has been freed from its cooperating wedge 11, such wedge 11 can be raised until its bore 14 is in registration with aperture 13 in the way shown at the right of FIG. 2, and such wedge can then be held in such position by inserting the pin 12 through the apertures 13 and 14, as shown in the upper portion of FIG. 3.

When each wedge l 1 has been raised and secured to the ways 10 by a pin 12, as indicated in FIG. 4, each of the wedges 3 can be moved upward again and secured to the brace slat l by a pin 4. The brace slats 1 and 9 will then be held in spaced relationship only by the pressure of the compression springs 15. Consequently, the brace slats can be readily moved manually from such expanded condition of FIG. 4 to the contracted condition of FIG. 5, and the pins 22 inserted in their respective clevises 21 and through appropriate lengths of the tie chains 19 to restore the brace slats of the dunnage to the contracted relationship shown in FIG. 5. Each dunnage unit can then be removed and stored or transported for reuse.

I claim:

1. Self-tightening dunnage comprising spaced parallel brace slats placeable in the space between separated load components and engageable respectively therewith, resilient means urging said brace slats apart to effect expansion of the space between said brace slats when such load components move to increase their separation, and wedging means reacting between said brace slats, substantially incontractable by compressive pressure thereon for preventing appreciable approach movement of said brace slats, but self-expanding as said brace slats are moved apart by said resilient means to deter return contraction of the space between said brace slats following such expansion of the space between said brace slats.

2. The self-tightening dunnage defined in claim 1, and tie means for connecting the brace slats in a contracted condition when not in place between load components to limit their separation from such contracted condition effected by the resilient means but said tie means being releasable while the resilient means are urging the brace slats apart for spreading of the brace slats beyond such contracted condition when the brace slats are placed between such separated load components.

3. The self-tightening dunnage defined in claim 2, in which the tie means are readily releasable after the brace slats have been placed between separated load components for spreading of the brace slats by the resilient means.

4. The self-tightening dunnage defined in claim 1, in which the resilient means includes at least two resilient members spaced lengthwise of the brace slats.

5. The self-tightening dunnage defined in claim 4, including resilient members located adjacent to the upper and lower ends respectively of the brace slats.

6. The self-tightening dunnage defined in claim 4, in which the resilient means includes a compression spring having one end secured to one brace slat and its opposite end bearing against the other brace slat.

7. The self-tightening dunnage defined in claim 1, in which the wedging means includes pairs of cooperating wedges relatively slidable between the brace slats, the wedges of each pair being engageable to prevent approach movement of the brace slats and consequent contraction of the dunnage.

8. The self-tightening dunnage defined in claim 7, and securing means securing one wedge of each pair to one of the brace slats, the other wedge of each pair being slidable lengthwise of the brace slats relative to such secured wedge.

9. The self-tightening dunnage defined in claim 8, in which the securing means is disengageable to enable the secured wedge of each pair to move relative to the brace slats.

' 10. The self-tightening'dunnage defined in claim 8, and second securing means for releasably securing the slidable wedges of each pair to a brace slat for preventing sliding movement thereof relative to such brace slat.

- 523 a UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION I Patent No. 3,788,498 Dated January 29 1974 Inventor) Leonard G Slusher i I I It is certified that error appears inthe above-identified patent I and that said Letters Patent are hereby corrected as shown below:

Colujmn 4, lines 15 through 17, claim 5 reads as follows I 5. The self-tightening dunna'ge defined in claim l, in which the'resilient means includes resilient members I located adjacent to the upper and lower ends, respectively,

of the brace slats.

v e canoe 1 -Y"4";land insert --1--.

'(sEAL) l I I Attest: v H I I MCCOY; M. GIBSON,- JR. w x I C'.--MARSHALL DANN; .Attesting Officer Commissioner of Patents 

1. Self-tightening dunnage comprising spaced parallel brace slats placeable in the space between separated load components and engageable respectively therewith, resilient means urging said brace slats apart to effect expansion of the space between said brace slats when such load components move to increase their separation, and wedging means reacting between said brace slats, substantially incontractable by compressive pressure thereon for preventing appreciable approach movement of said brace slats, but self-expanding as said brace slats are moved apart by said resilient means to deter return contraction of the space between said brace slats following such expansion of the space between said brace slats.
 2. The self-tightening dunnage defined in claim 1, and tie means for connecting the brace slats in a contracted condition when not in place between load components to limit their separation from such contracted condition effected by the resilient means but said tie means being releasable while the resilient means are urging the brace slats apart for spreading of the brace slats beyond such contracted condition when the brace slats are placed between such separated load components.
 3. The self-tightening dunnage defined in claim 2, in which the tie means are readily releasable after the brace slats have been placed between separated load components for spreading of the brace slats by the resilient means.
 4. The self-tightening dunnage defined in claim 1, in which the resilient means includes at least two resilient members spaced lengthwise of the brace slats.
 5. The self-tightening dunnage defined in claim 1, in which the resilient means includes resilient members located adjacent to the upper and lower ends, respectively, of the brace slats.
 6. The self-tightening dunnage defined in claim 1, in which the resilient means includes a compression spring having one end secured to one brace slat and its opposite end bearing against the other brace slat.
 7. The self-tightening dunnage defined in claim 1, in which the wedging means includes pairs of cooperating wedges relatively slidable between the brace slats, the wedges of each pair being engageable to prevent approach movement of the brace slats and consequent contraction of the dunnage.
 8. The self-tightening dunnage defined in claim 7, and securing means securing one wedge of each pair to one of the brace slats, the other wedge of each pair being slidable lengthwise of the brace slats relative to such secured wedge.
 9. The self-tightening dunnage defined in claim 8, in which the securing means is disengageable to enable the secured wedge of each pair to move relative to the brace slats.
 10. The self-tightening dunnage defiNed in claim 8, and second securing means for releasably securing the slidable wedges of each pair to a brace slat for preventing sliding movement thereof relative to such brace slat. 